Be quiet!, a power supply manufacturer based in Germany, has announced that almost all of its recent power supply lineups are fully compatible with Intel's upcoming Haswell processors. The PC Perspective team has talked in-depth about the new C6 and C7 sleep states used by Haswell CPUs. However, for the uninitiated, the new Intel processors have two new low power sleep states. The lowest state, C7, draws as little as 0.05A from the 12V PSU rail. That is a good thing, but not all power supplies will be compatible with the new sleep states as such low load on the 12V rail was not a concern when the PSUs were designed and manufactured. Notably, even incompatible power supplies will still work in Haswell systems, but those computers will not be able to enter the lower-power C6 and/or C7 sleep states.

There is good news for users of Be Quiet! Power supplies, however. The following power supplies are fully compatible with Haswell and the new sleep states:

Dark Power Pro 10 Series (all models)

Straight Power E9 Series (all models)

Pure Power L8 Series (all models)

System Power 7 Series (all models)

Pure Power L7 Series (the 630W and 730W models only)

Older Be Quiet! power supplies will still work in Haswell systems, but use of the lowest power C7 state is not recommended. Fortunately, most desktop users can live without the new low power states (which, while nice to have, the new sleep states are more beneficial to laptop users).

As the launch of Haswell approaches, more and more PSU manufacturers are releasing compatibility information. So far, the following companies have put together compatibility lists.